The present invention relates to measurement probes, and more particularly, to probes for measurement of anisotropic magnetoresistance characteristics of thin films and the like.
The anisotropic magnetoresistance of a thin metal film is a sensitive measure of the quality of the film. When the films are to be used in the development of devices that use the magnetoresistance, it becomes necessary to measure that quantity on every film. The measurement must therefore be made easily and without damaging the film in the process.
Heretofore, the techniques commonly used to measure the sheet resistance of a thin metal film either cannot measure the magnetoresistance or destroy the film in the process of measuring it. One technique is etching or cutting the film into a strip and making two or four wire resistance measurements on the strip. This technique can measure the magnetoresistance, but it leaves the film in an unsuitable condition for further processing. The second technique is to make contact with the film at four collinear points, using a device called a four-point probe, and make voltage versus current measurements. This method is nondestructive but is not sensitive to the anisotropic magnetoresistance. The third technique is to process the film to produce a small magnetoresistive device on a small portion of the film and then test this device. This approach requires considerable processing to be accomplished on the tested thin film which might be discarded for failing the test.
Additionally, the results measured on a small portion of the film using this produced device may not be representative of the rest of the area of the thin film under test.
Accordingly, it is desirable to provide a device and method for measurement of magnetoresistance parameters of thin films which overcomes the deficiencies of the prior devices and methods discussed hereinabove.
Accordingly, it is an object of the present invention to provide a device and method thereof for measurement of magnetostrictive parameters in thin films at an early stage of production in a non-destructive manner. Further objects and advantages of the present invention will become apparent as the following description proceeds and features of novelty characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.